#include <stdio.h>

int main(void)
{
    float commission, value;

    do {
        printf("Enter value of trade: ");
        scanf("%f", &value);
        if (value > 0) {
            if (value < 2500.00f)
                commission = 30.00f + 0.017f * value;
            else if (value < 6250.00f)
                commission = 56.00f + 0.0066f * value;
            else if (value < 20000.00f)
                commission = 76.00f + 0.0034f * value;
            else if (value < 50000.00f)
                commission = 100.00f + 0.0022f * value;
            else if (value < 500000.00f)
                commission = 155.00f + 0.0011f * value;
            else
                commission = 255.00f + 0.0009f * value;

            if (commission < 39.0f)
                commission = 39.0f;
            printf("Commission: $%.2f\n\n", commission);
        } else
            break;
    } while (value != 0);

    return 0;
}
